Graduation date: 1995

Hydro-climate extreme analysis helps understanding the process of spatio-temporal variation of extreme events due to climate change, and it is an important aspect in designing hydrological structures, forecasting floods and an effective decision making in the field of water resources design and management. The study evaluates extreme precipitation events over the Columbia River Basin (CRB), the fourth largest basin in the U.S., by simulating four CMIP5 global climate models (GCMs) for the historical period (1970-1999) and future period (2041-2070) under RCP85 GHG scenario. We estimated the intensity of extreme and average precipitation for both winter (DJF) and summer (JJA) seasons by using the GEV distribution and multi-model ensemble average over the domain of the Columbia River Basin. The four CMIP5 models performed very well at simulating precipitation extremes in the winter season. The CMIP5 climate models showed heterogeneous spatial pattern of summer extreme precipitation over the CRB for the future period. It was noticed that multi-model ensemble mean outperformed compared to the individual performance of climate models for both seasons. We have found that the multi-model ensemble shows a consistent and significant increase in the extreme precipitation events in the west of the Cascades Range, Coastal Ranges of Oregon and Washington State, the Canadian portion of the basin and over the Rocky Mountains. However, the mean precipitation is projected to decrease in both winter and summer seasons in the future period. The Columbia River is dominated by the glacial snowmelt, so the increase in the intensity of extreme precipitation and decrease in mean precipitation in the future period, as simulated by four CMIP5 models, is expected to aggravate the earlier snowmelt and contribute to the flooding in the low lying areas especially in the west of the Cascades Range. In addition, the climate change shift could have serious implications on transboundary water issues in between the United States and Canada. Therefore, adaptation strategies should be devised to cope the possible adverse effects of the changing the future climate so that it could have minimal influence on hydrology, agriculture, aquatic species, hydro-power generation, human health and other water related infrastructure.

I sought to determine the effect of managed flooding on Phalaris arundinacea L. and other plant species distributions in a large wetland complex, Smith and Bybee Wetlands (SBW), in northwestern Oregon. Altered hydrology has reduced historically high spring flow and prematurely initiated the historic summer drying period at SBW. This alteration has increased the coverage of invasive plants (e.g., P. arundinacea) causing a decrease in native plant cover and thus degrading ecological functions. SBW managers installed a water control structure (WCS) between SBW and the Columbia Slough/River system to impound winter rainfall and thus approximate the ecological benefits that natural flooding provided as well as reduce the abundance of P. arundinacea. Prior researchers conducted intensive vegetation and hydrological monitoring in 2003 (during the season immediately before WCS installation) and 2004. I conducted similar analysis in the fifth and sixth years, 2008 and 2009, following establishment of the WCS. Both study years, I determined percent cover of all vegetation on transects established in 2003. The results, including 2004, as well as 2008 and 2009 showed a reduced cover of P. arundinacea in areas experiencing at least 0.6 meters of inundation and an increased cover of native plant communities when compared to the 2003 baseline data. Native Carex aperta Boott. cover increased 7-fold from 0.3% to 2.3%; Polygonum species cover increased from 20.0% to 52.6%; and Salix lucida Muhl. ssp. lasiandra (Benth.) E. Murray cover increased from 10.9% to 15.5% cover. P. arundinacea declined by over one-third from 44.4% to 28.1% cover following water management. Since hydrology management began, the native Polygonum species community replaced P. arundinacea as the dominant species in the emergent zone. The results of this study refined the suggested depth of inundation needed to reduce P. arundinacea cover in such lake-wetland complexes as SBW from 0.85 meters (based on 2004 study results) to 0.6 meters. Shannon Diversity decreased following water management. The findings of this study demonstrated that water management can enhance native bottomland communities, especially those comprised of obligate wetland species, and reduce P. arundinacea cover in areas experiencing at least 0.6 meters of inundation.

Numbers of wild Canada geese (Branta canadensis) have increased dramatically during the past 30 years in the lower Columbia and Willamette Valley systems. The damage they cause by grazing and trampling plants can be substantial. The objectives of this research were to: 1) Develop methods that provide reliable estimates of goose impact on wheat yield and quality, and 2) Develop methods to separate goose damage from other factors that lower yield such as poor soil or waterlogging. To document grazing impacts, color aerial photography was combined with Global Positioning System (GPS) and precision farming technology. Field-scale color aerial photographs (1:14,000 scale) were acquired four times during each growing season: in January, March, April, and just prior to harvest in July. Each flight was coupled with ground truth data collection to verify exact cause of spectral signature variation or variations in wheat cover. Such data included wheat height, number of goose droppings, and a relative rating of goose grazing intensity. At each sampling point a platform photograph and a GPS location were taken. Wheat yield impact varied considerably as field size, shape and proximity to road varied. Yield maps revealed that, goose grazing had reduced grain yield by 25% or more in heavily grazed areas. At harvest time during the first year, wheat grain in the heavily grazed areas had higher moisture content due to delayed maturity. Therefore those areas were harvested two weeks later. Heavily grazed areas also had more weeds than ungrazed portions of the field. Late-season (April) grazing was more damaging to wheat yield than was earlier season grazing, but early season grazing did have an impact on yield. Intensely hazed fields had lower levels of damage than did fields or portions of fields that were not as vigorously guarded. Our results illustrate very practical ways to combine image analysis capability, spectral observations, global positioning systems, precision farming and ground truth data collection to map and quantify field condition or crop damage from depredation, standing water, or other adversities. Image analysis of geopositioned color platform photographs can be used to stratify winter wheat fields into impact units according to grazing intensity. Ground-truth data, when collected in conjunction with a GPS, provided the information needed to locate and establish the spectral properties of impacted areas. Once the spectral properties of a representative area were identified, information could be extrapolated to other areas with the same characteristics. In addition, this method could be used in conjunction with aerial photography to verify areas of grazing. The combination of two or more of these tools would provide farm managers and agricultural consultants with a cost-effective method to identify problem areas associated with vegetation stress due to heavy grazing by geese or other factors. / Graduation date: 1999

This thesis explore the technological role of bone and antler artifacts from two contact period southern Northwest coast archaeological sites, the Cathlapotle site (45CL1) and the Meier site (35CO5). Technological measures of sedentism are based on lithics, and predict residential sedentism promotes technological expediency in hunter-gatherers (Parry and Kelley 1987). Cathlapotle and Meier lithic assemblages consist of expedient and opportunistic assemblages and raw material stockpiles, with the exception of highly curated projectile points and endscrapers (Hamilton 1994). The expectation that residential sedentism promotes technological expediency in hunter-gatherers was tested on the Cathlapotle and Meier bone and antler artifact assemblages in two ways. First, curation and expediency were recorded for each artifact by measuring level of energy investment in manufacture or degree of working. Second, a spatial analysis was used to explore methods of artifact storage and disposal. Results revealed both Cathlapotle and Meier osseous assemblages are highly curated, except for expedient awls and flakers. Specifically, artifact classes related to subsistence procurement, modification including woodworking, and ornamentation were highly curated. Both sites contain stockpiles of unmodified bone and antler. The spatial analysis showed level of curation did not affect artifact disposal method. Despite this, some patterns were evident. At Cathlapotle, curated procurement and modification artifacts, expedient awls as well as worked fragments were concentrated outside the houses, specifically in Sheet Midden. Broken modification artifacts, ornaments, and detritus were randomly distributed. At the Meier site, curated procurement and modification artifacts, as well as expedient awls were randomly distributed. Broken modification artifacts, detritus and worked fragments were concentrated outside the houses. Ornaments were concentrated in the northern segment (elite area) of the house. There were also significantly more curated complete tools recovered from the cellar facility, while significantly fewer curated complete tools were recovered from the midden facility at Meier. In this thesis, the effects of contact on osseous assemblages were examined. It is an assumption of North American archaeologists that European-introduced metals replace and/or change the character of traditional technologies such as lithic and osseous technologies. Few quantitative studies comparing pre and postcontact artifact assemblages exist (Bamforth 1993, Cobb 2003). In some parts of northeast North America, European contact is followed by a proliferation of osseous tool working, and over time osseous artifacts drop out of the archaeological record (Snow 1995, 1996). Cathlapotle and Meier were occupied from AD 1400 to AD 1830, spanning European contact. People at Cathlapotle were in direct contact with Europeans and Euro-Americans since 1792 (Boyd 2011). Previously, it was assumed Cathlapotle was more involved in the fur trade than Meier, because Cathlapotle was mentioned several times in ethnohistoric accounts, while Meier was never mentioned. Also Cathlapotle contains far more historic trade items than Meier (Ames 2011). The assumption that European-introduced metals replace and/or change the character of traditional technologies was tested on the Cathlapotle and Meier assemblages by comparing artifact frequency, density, and assemblage diversity of pre and postcontact assemblages. Results show contact is reflected in the osseous assemblages at both Cathlapotle and Meier. Contact is evident, but is reflected in different ways. At Cathlapotle, artifact frequencies, densities, and assemblage diversity decrease postcontact. In contrast at Meier, artifact frequencies and densities increase postcontact, with some artifact classes tripling or quadrupling in frequency. The introduction of metal could have enabled people to work osseous materials faster and easier, decreasing manufacture time, cost, and overall energy investment. The gain in efficiency promoted the proliferation of bone working and an abundance of osseous tools at the Meier site. These results encourage a reevaluation of Meier's role in the fur trade. At Cathlapotle, metal objects may have replaced osseous tools resulting in the decline of bone and antler working and/or activity patterns shifted away from activities requiring osseous tools. The results of this thesis deviate from typical Northwest Coast bone and antler assemblages, challenge technological models of sedentism that are based on lithics, and contradict assumptions of Lower Columbians involvement in the fur trade.

The Columbia River Gorge National Scenic Area (NSA) was created in 1986 in response to a growing interest in preserving the scenic beauty of the gorge. The creation of the NSA and other areas around the country with a scenic resource emphasis indicates a growing interest in protecting landscapes with diverse scenic qualities that are not showcase areas such as the Grand Canyon and Yosemite. NSA mandates included the protection and enhancement of scenic, natural, cultural, and recreational resources (SNCRs) as the primary concern in the consideration of new land uses. The NSA management plan contains a complex mix of management tools for the protection of SNCRs in the gorge. This research was an investigation into how scenic resources policy was developed, with a focus on the scenic resources of the NSA. One issue was the definition of scenic resources, which are undefined in the management plan. Because of the difficulty of identifying scenic resources, other resources may be managed as a surrogate for them. An analysis was made of the scenic resources management schemes of several federal reserve lands with a stated scenic management objective to determine if this was the case, and to compare their management strategies for the NSA. A second issue was the public's understanding of what constitutes a scenic resource and the role that public input had in the development of the management plan. Empirical work suggests that complexity of issues may hinder successful public input processes. A final issue was how identifiable stakeholders in the Columbia River Gorge differed in their views on scenic resources, which may depend on their proximity to and relationship with such resources. Results of data analysis and the interview process reveal that public understanding about scenic resource concepts is low, and that gorge planners were primarily responsible for development of scenic resources policy in the NSA management plan. As expected there were some identifiable differences in the views on scenic resources among various stakeholders. Scenic resources management elsewhere is done primarily through traditional zoning requirements, and the basis of management of scenic resources appears to be for other culturally-defined purposes such as recreation.

Located in the Columbia River Gorge, The Red Bluff Landslide (18.8 km2) is one of four large landslides that make up the Cascade Landslide Complex. In its current form, the Red Bluff Landslide is a post-Missoula Flood feature made up of two components: an active upper lobe (8.6 km2) that is translational, creeping to the south at 25 cm/yr and spreading laterally to the east at 6 cm/yr over a semi-fixed portion (10.2 km2) of the Red Bluff Landslide area that has been "smoothed" by Missoula Floods. The upper active lobe is the landslide debris accumulated since Missoula Flood time (~15,000 yr. BP). Five separate collapse events have been identified and rock failures along the main scarp headwalls continue. Two rock avalanches on the Red Bluff Landslide were mapped. The Old Greenleaf Basin Rock Avalanche is estimated to have occurred 100 to 150 years ago, represents the fifth collapse event on the Red Bluff Landslide, and covers an area of 200,000 m2. It has a volume of 4.2 million m3; its length is 748 m and has a width of 215 m. On January 3, 2008, the Greenleaf Basin Rock Avalanche occurred, flowing over the Old Greenleaf Basin Rock Avalanche, covering an area of 100,000 m2 and deposited a volume of about 375,000 m3. Its length is 730 m with an average depth of 1.22 m. It contributed approximately 0.058% of the total volume and 0.01% of the surface area to the active upper lobe portion of the Red Bluff Landslide. The Greenleaf Basin Rock Avalanche was determined to be insignificant in the movement of the active part of the Red Bluff Landslide during the winter of 2007-2008. The original Cascade Landslide Complex map (Wise, 1961) included the Mosley Lakes Landslide which has now been removed because it lacked the characteristics of a landslide like a scarp. The original complex (35.5 km2) has been renamed the "Greater Cascade Landslide Complex" (43.0 km2), with the addition of the adjacent Stevenson Slide and the elimination of the Mosley Lakes Landslide.

Anthropogenic reactive nitrogen is emitted into the atmosphere from fossil fuel combustion (nitrogen oxides) and agricultural activities (nitrogen oxides and ammonia). Nitrogen oxide emissions have long been controlled for their role in ambient air pollution and human health effects. However, reactive nitrogen deposition is less understood even though it can play a significant role in altering biodiversity, impairing ecosystem and biogeochemical function and degrading cultural artifacts. Although nitrogen deposition is a natural part of biogeochemical cycling, many ecosystems across the United States are at risk of exceeding the critical nitrogen deposition load. While nitrogen oxides are routinely measured in urban areas, far less is known in non-urban landscapes where ecosystems may be especially sensitive. Regional chemical transport models have been used to predict the impacts of ambient reactive nitrogen deposition in non-urban areas, but models have difficulty simulating reactive nitrogen due to poorly quantified emissions, especially from the agricultural sector. My research explores the speciated deposition of reactive nitrogen through monitoring and modeling in the unique field setting of the 150 mile Columbia River Gorge (CRG) located along the border of Oregon and Washington. This site is ideally suited for this investigation due to the large sources of reactive nitrogen at either end of the CRG and unique seasonally driven channel wind flow. Seasonally driven wind allowed us to look at the reactive nitrogen emissions flowing through the CRG to assess ambient the reactive nitrogen partitioning and deposition gradient. Using data collected by the United States Forest Service to control ambient haze in the CRG and our co-located nitrogen oxides (NOx) gas analyzer, we first characterized the influence of seasonal, bimodal wind distributions on the spatial distribution of reactive nitrogen. We found that during winter months with predominantly easterly winds, particulate nitrate and ammonium and gas-phase nitrogen dioxide levels create a gradient from the eastern end to the western end. Particulate nitrate and sulfate mass concentrations influence the CRG gradient during summer months with predominantly western winds. We also found that the magnitude of the impact from east is greater than the magnitude of impact from the west. When we compared our observations to regional chemistry transport models, we found that models are significantly under-predicting levels of reactive nitrogen in the CRG. This bias is not isolated to a single station within the Gorge, but throughout the whole Columbia Basin. Our results indicate that there are under-represented emissions in the region leading to this bias. Partly due to the bias in reactive N gas-phase species in the CRG, regional models have been underestimating the impact of gas-phase reactive N on dry N deposition. We conducted field studies at two sites within the CRG monitoring reactive nitrogen species (nitric oxide, nitrogen dioxide, ammonia, nitric acid, particulate nitrate, particulate ammonium, and particulate sulfate) as well as ozone and meteorological parameters. These measurements allowed us to conduct the first comprehensive analysis of reactive nitrogen partitioning and deposition in the CRG. Through our measurements, we found reactive nitrogen was higher in the spring than the summer. We found concentrations ranging from 0-15 ppbv ammonia, 0-7 ppbv nitric acid, 0-2 µg/m3 ammonium nitrate and 0-1 µg/m3 ammonium sulfate at the sites. Through the measurements of all these species, we evaluated the limiting gas-phase precursor to inorganic nitrogen particle formation. In the springtime, ammonia limits the formation of particulate reactive nitrogen; while in the summer, nitric acid and oxidized sulfur limit the formation of inorganic nitrogen particles. This suggests that there may be more sources of ammonia in the spring with fertilizer application or perhaps reactive nitrogen reservoirs are renoxified through thermal dissociation during warmer summer months. Our estimated deposition from gas and particle phase reactive nitrogen ranged from 0-0.14 kg N/ha per day. We also found that gas-phase reactive nitrogen plays the largest role in dry N deposition in the CRG with particle-phase contributing less than 15% of total dry N deposition. These results are important for land managers to understand the total impact of reactive nitrogen to non-urban areas. This research can inform mitigation strategies for haze formation, identify the major species and sources involved in dry N deposition and assess the potential impacts to ecosystems and cultural artifacts.

Groundwater temperature data, collected at an alluvial terrace located on the Oregon shore of the Columbia River downstream from Bonneville Darn, was analyzed in order to characterize and formulate a conceptual model of the thermal data for the groundwater system in the terrace. There is concern that an unlined entrance channel for a new navigation lock, to be located down the middle of the terrace, will widen the range of temperatures in the fish hatchery-groundwater supply. The analysis of temperature behavior in the terrace supports the hydraulic observations derived from analysis of pump test data, but with greater definition of the more subtle behavior of the groundwater system not readily discernible in the pump test data. The thermal behavior of the terrace groundwater system is governed by: 1) the stratigraphy of the terrace, 2) its groundwater recharge characteristics, 3) thermal influence from the Columbia River, and 4) stress placed on the aquifer system due to pumping of fish hatchery wells located in the terrace.

This paper traces the history of Oregon Trout, an environmental organization in Portland, Oregon, from its beginning in the fall of 1983 through the spring of 1990, when it filed petitions on behalf of four stocks of Columbia and Snake River salmon under the Endangered Species Act. It focuses on Oregon Trout's efforts to preserve the wild salmon of the Columbia River as a contemporary example of anglers acting as environmentalists to conserve threatened or endangered species. According to historian John Reiger in American Sportsmen and the Origins of Conservation, hunters and anglers have been acting in this role in the United States since the Civil War, well before the Progressive Era in which the conservation movement is generally thought to have originated. However, the paper contends that Oregon Trout's advocacy for the interests of fish rather than fishermen is unique in the tradition to which Reiger points.